The Tumor Growth Process

The complexity of the tumor growth process involves many different phenomena. There are two main phases in this process; avascular and vascular. Tumor cells need oxygen and nutrients for proliferation, in the first phase, these supplements are provided by diffusion through the surrounding tissue. This is sufficient till the tumor size reaches to 2-3 millimeters and cells will need more supply. In this stage, the cells in the center of the tumor are exposed to the lack of oxygen and nutrients and form a necrotic core6. In order to survive and continue the proliferation, tumor cells need their own blood supply, therefor, they start to secrete some growth factors; The receptors on the nearest blood vessel respond to these factors and new micro
When one knows about the outcome of different therapies for a specific patient, they can choose the best plan so that the patients expose to fewer side effects and experience a life with higher quality. Since the information available from image observations are mostly at macroscopic scale, we only review models in macroscopic scale which can mainly be divided into two groups: with and without considering mass effect. Then we will focus on the studies with image-based source of
New functional imaging techniques integrate morphological, pathological and physiological alterations and are used as early predictors of the therapeutic response. They allow earlier assessment of therapy response by observing alterations in perfusion, oxygenation, and metabolism. The imageable information of the tumor depends on the tumor cell distribution and the imaging modality 44,45. In this section a brief description of usual modalities which are used in diagnosis, response assessment and follow-ups in oncology, is